Check ABI regardless of arch variants

The ABI reference dump directory names contained TARGET_ARCH_VARIANT
or TARGET_2ND_ARCH_VARIANT. The builds with non-generic arch variant
could not find the reference dumps for their arches. This commit renames
the directories to <TARGET_ARCH> and <TARGET_2ND_ARCH>_<TARGET_ARCH> to
ensure that all arch variants are checked.

Bug: 213127415
Test: lunch aosp_cf_x86_64_phone-userdebug && make

Change-Id: I7617f3ffc0e1bc423eea8c39e0f2b745276b4244